Vast Coastal Lake Chain in Brazil and Uruguay Proposed as Early-Warning Network for Ecosystem Stress

Scientists have identified a 1,000-kilometre stretch of shallow lakes along Brazil and Uruguay’s Atlantic coast as a potential natural observatory for detecting early signs of climate and pollution impacts.

A new study released in the journal One Ecosystem maps more than 100 lakes spanning over 1,000 km of the Atlantic shoreline of southern Brazil and Uruguay, describing the system as a unique natural laboratory for freshwater research. Because these shallow lakes are simultaneously exposed to climate cycles, rapid urbanisation, agricultural runoff, untreated wastewater, pharmaceuticals and micro-plastics, they offer a rare chance to observe how complex stressors affect ecosystem resilience.

The authors propose treating the lake chain as a “sentinel ecosystem,” employing methods such as eDNA profiling, microbial ecology, satellite imagery and long-term ecological observations to detect early biological and chemical changes. The initiative was shaped at a joint workshop in Porto Alegre with scientists from Brazil, Uruguay, Germany and Sweden, who selected four representative regions to anchor future monitoring efforts.

If successful, the network could provide continuous data on biodiversity loss, water-quality degradation and climate impacts, enabling policymakers to intervene before irreversible tipping points are reached. Images accompanying the release were supplied by iStock.